1. Field of the Invention
The present invention is directed to an article such as a collar having a setscrew opening and to the method of making the article.
2. Prior Art
In many instances, collars having setscrews are utilized on shafts to either locate the shaft in a supporting structure or to maintain a critical position of a part carried by the shaft. At the present time, collars are usually cut from bar stock and the setscrew hole is formed by drilling and tapping operations. This method of forming a collar or other articles requires expensive machining processes which increase the cost of the article.
To provide an article which can be held onto a shaft by a setscrew without requiring expensive drilling and tapping operations, it has been suggested to form the article as a block member with a groove having a partial annular section of threads which threads cooperate with a retaining clip subsequently assembled on the block to complete the setscrew hole. An example of this article is disclosed in U.S. Pat. No. 3,600,013 which issued to J. P. Doering on Aug. 17, 1971. While the structure of this article removes the need for expensive steps of drilling and tapping a setscrew hole, it requires an additional step of assemblying the clip onto the body of the article to complete the setscrew hole.
In the powder metallurgy art, several processes have been utilized to form complex structures, for example a valve sleeve which has ports and is disclosed in U.S. Pat. No. 3,353,249 which issued to MacFarlane et al. on Nov. 21, 1967 or a pulley wheel which has helical teeth and is disclosed in the U.S. Pat. No. 3,429,700 which issued to Wiegand et al. on Feb. 25, 1969. In both of these processes, the final article is subdivided into components which are formed by compacting metal powders with a subsequent sintering operation and then the subcomponents are joined together by a bonding process to complete the article. While the process disclosed in both of these patents, enable producing radially extending ports or other complex configurations, each process requires a step of joining the subcomponents to form the final article. Thus, while eliminating many machining steps these disclosed processes still require assembly or joining steps which prevent a sizable reduction in the cost of the article.